Bite makes way for brain

A pile of evidence from disparate disciplines indicates that a single change in a single gene—MYH16—may be responsible for significant morphologic differences between humans and other primates, including possibly the increase in brain size that set the earliest species of Homo apart from their kin. This is the first protein disparity between humans and chimps that can be correlated to drastic anatomical changes seen in the fossil record, according to a group of University of Pennsylvania researchers who published a letter in the March 25 issue of Nature.

“This is a brilliant piece of detective work that has enormous implications for medicine, biology, evolution, molecular genetics, [and] the human genome,” said Frederick S. Kaplan, a professor of orthopedic molecular medicine at Penn who was not part of the study. “By relegating a gene to the evolutionary garbage heap, we were able to lift the constraints to the development of human ...